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1 UNI-Te STATES PATENT? OFFICE.-

ALBERT DOMEIER AND OTTO or-IRIs'rIAN 'nAe M Nn-or LONDON,. ENG--- LAND; ASSIGNORS ,TO JAMEs KIRK & 00.,- or CHICAGO, ILLINOIS."

Process or; RECOVERlNG G tYCERI NE AND-s ur 550M sPEN-t SOAE-LYE.

srncxrme'rfon forming m r'rs Patent No. 453,829, dated an; 9, 1891;" i Application filed'Septe nber 26,1390. Serial lie. 366,257. (lie specimens.) Patented in i E'ranoe; April 24,1889 Ila 197.713.

To aZZ whom it may concern:

Be it known that we, ALBERT DOMEIER, merchant, and OTTO CHRISTIAN HAGEMANN chemical engincef,-both subjects of the Queen of Great- Britain, and residing at London, Eng-Q land, have invented certain new and useful Improvements in Recovering Glycerine-and Salt from Spent Soap-Lye, of which the following is a specification.

The object of this invention is to provide an imprcvedprocess for removing the impurities from spent soap-lye to, facilitate the recovery of crude g'lycerine ahdsalt therefrom.

I It the spent lye contains an appreciable quantity of alkali worth recovering, we' prefer, first, to make meet such alkali in manner prescribed in Letters Patent of the United States No. 385,105, dated J une .26, .1888. Whether this preliminary step'has been taken or not, we next proceed as follows: We take: the lye into a convenient tank or similar re-- ceptacle, and there neutralize anyfree alkali by meansof a suitable acid, such as hydroclilorictor sulphuric acid. \Ve next-add to it a small proportion of a suitable metallic oxide or hydroxide-such as that of iron or baryta capable of decomposing soapy matters and .combining with, the fats therein contained to "form insoluble metallic soaps. 'lhe proportion of such oxide varies with the character of the spent lye under treatment, and should always be sufficient or just a'littledm excess of the quantity required to combine with all -the fatty matters contained in the lye. For instance, we have found from eight to fourwteen pounds of hydrated oxide of iron suffi- ,cient for one ton of spent lye. The proper proportion of the oxide may be added to the lye first, and the acid to neutralize the lyeafterward, if so preferred, and additional quantities of acid added from to time to neutralize the alkali set free by the oxides, as more fully stated below. We next thoroughly mix or agitate the oxide with the neutralized lye. This can be elfected by mechanical agi- ;tation,0r by preference'byblowingairthrough it. We maintain this agitation const'antlyor accomplish it at frequent intervals duringthe time necessary to complete the reaction, which maybe quicken ed by heating thcliq'uor equivalent.

to 7 0 or'8U centigrade. fills the prbcesspro I eceds the liquor becomes alkaline by reason of the decomposition of theisoapy matter'sjby,

perature of about 15Q'centigrade,thus prodhcingcrud glycerine fit for distillation Without further treatment, and salt which crystallizes during the'concentration and which can be washedand made avai'lab le f-oi';

use again in the arts. l w v In-order that the, process may be fully un- 1 .centrate the clear liquor by boiling to a terndersto'od,we will'reeapitulatethe variousstcps Where chemical reactions? o cc'ur.' a i First, by neutralizing the lye albul ninou's. matters are precipitated; second, byadding a suitable metallic oxide with agitation andcorrecting the" alkalinity of the liquor from time to timeby'the addition of acid'the's'oapy matters'are decomposed and the 'fattyacids therein combine with the metallic oxides, the

alkali set free forming, with the acid, salt which is recovered inthe subsequentconcentration. It will thus be seen that the crude glycerine and salt are extracted from the lyeand that the salts produced by' the union of the chemicals employed are also rec0vered.=

The process is particularly Welladapte'd to I small soap factories, as no expensive lead-lined ing operation can be conducted entirely-in one-vessel. i r

, We do not confi oxides'or earthy metallic oxide'mentioned;

oxide or hydroxide Weclain1 1. In the recovery of glycclineand saltlirom no on rseii es to the metallic 9'5" "but any suitable metallic or earthy metallic;

is regarded byus as their 4 9 tanks or the like are requiredandthe purify- I spent soap-lye, the -imprbyement which 00111- sists in neutralizing thefreeelkali in the lye with acid and treating it with a Suitable mefallic xide ofhydroxide capable bf deempposing soapy matters.

2,. In thet'ecoveryof glycerineand-salt froth f spent soap 1ye, the improvement which consi sts; inineutralizing thefree alkaliin "thely'e with acid and decomposing' the soapymatterl therein by liquorfram the precipitate. In the recovery pf glyeo'rineaml-saltflom treatment with suitable oxide'sjota "hydroxides, adding acid to neutralize the alkali thus set free, and-sepatfxting the-clear s p ehtSoap-Iyeflhe improvement which eon .s'istsjn neutmlizing the free alkaliin the lye \vifl l- "acid; decomposing v the soapym atters therein by treatmentwith a. suitable oxide or hbdrox-id e, addig acid to heu ttalize the alkali thus setflfre, andrfinztlly separating andcon- 2o ce'nt-rating-the' clear liquor.

- ALB RT DOMEIEQR."

0m CHRIS'IIAN nmmimv;

Ti tn esses: V

O IVER R. J OHNSON, v A.'G.'1\IUMFORD, 'f O'onsulute-General, A., London. 

